The present invention relates generally to the control of a microturbine and specifically to a control capable of starting the microturbine as well as matching the microturbine electrical output to an external power bus.
In a wide variety of applications, microturbines are used to provide power to an external power bus. The external power bus may be, for example, a national or regional power grid, or a more localized power distribution system such as, for example, a shipboard or aircraft power grid. The microturbine typically comprises a Brayton cycle engine prime mover mechanically coupled to an alternator with the alternator configured both to generate power and to serve as a starter motor for the engine.
At least two features distinguish the microturbine from other power generating systems. First, compared to larger gas turbine generating systems, the smaller microturbine runs at a substantially higher rotational speed and consequently generates power at an electrical frequency substantially higher than the usual 50 or 60 Hz of standard power grids. Second, compared to smaller household diesel generators, the larger microturbine is too unwieldy to start by hand. An opportunity exists, therefore, to provide a microturbine controller capable both of matching the microturbine electrical output to an external power bus and of driving the alternator as a starter motor from power derived from that same external power bus.